Improvement in insulators for telegraph-wires



2 Sheets-Sheet 1.

z. c. ROBBINS.

Insulator.

Patented Feb. 28, 1871.

tint

ZENAS C. ROBBINS, OF WASHINGTON, DISTRICT OF COLUMBIA.

Letters Patent No. 112.281, dated February 28, 1871.

IMPROVEMENT IN iNSULATORS FOR TELEGRAPH-WIRES.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern Be it known that I, Zazus G. ROBBINS, of Washington, in the District of Columbia, have invented a new and improved Insulator for Telegraphic Wires and I do hereby declare that the followingis a full and exact description thereof, reference being bad to the accompanying drawing which forms a portion of this specification, in which Figures 1, 2, 3, and A arc views of difl'erent sizes andstyles of said invention, partly sectional.

Figure 5, a sideview of'a detached portion of the same, termed the wire-holder; and f The other sheet of dmwing mostly illustrates the method of'constructing mysaid telegraph-wireinsnlator,-and assuch will be hereinafter referred to;

Mysaid-improved" insulator for telegraph-wires is composed of the metallic supporter a b, the wire-holder c c d c f, and the material g,which serves the purpose of combining the former with the latter, at the same time that it completely insulates the said metallic parts from each 'other. 7 Y

The body portion a of the metallic supporter a. I: must be open throughout, and.its sides must beofsuch a shape that they will securely retain any substance that may be placed therein while in a plastic or fluid state, and then allowed to harden therein. Glass, gutta-percha, or any other suitable combinmg and non'conducting material may beeniployed, as represented by g in the accompanying drawing, for V combining the wire-holder with and insulating the same frczm'the head-a of the body of the metallic supporter a Figs. 1. 2, and 3 represent-the proper size and proportions of the body a of the metallic supporter a b, when glass or any-suitable cement is to be employed as the material for combining the wire-holder with and insulating the same from the said body; and

Fig. 4 represents the proper size and proportions ofthe body of the said metallic supporter a b when gntta-percha is to be-employed as the material for com-. bining therewith the shank of the wire-holder.

The combining and insulating-material 9 may rise a little above the sides of the body a of the metallic supporter, as represented in figs. 1, 4, and 8; or it may be left flush with the upper end of the body of said supporter, as represented in figs. 2 and 3.

Figs. 1, 2, 3, and 4 represent a proper shape to be given to the bottom surface of the said combining and insulating-material g, to produce, under all circumstances, a perfectly insulating separation between the surface of. the wire-holder and the uncovered inner surface of that portion of the body a of thesnpporter that descends below the body of the said combining and insulating-material.

' insulating-material.

To give the said proper shape to the bottom surface of the combining and insulating-material g, and, at the same time, simplify and reduce the cost of manufacturing my said improved insulator for telegraphwires, I have invented the following process of manufacturing the same, to wit? I employ a molding-clamp composed of two sections, it h, of the shape represented by figs. (3 and 7 of the drawing- Figure 6 being a top view of the said clamp, and

Figure 7, an inside view of one of the sections thereof detached from its mate.

The longitudinal cavity in in each clamp-section h is the counter-shape of that of the semi-circninference ofthe body of the wiredioldei', and, consequently, the two clamp-sections h h can be made to closely embrace the body of the wire-holder, as shown in Figure 8.

The exterior shape of the united clamp-sections is such that the clamp will fit accurately within the lower portion of the open body of the metallic sup porter a b, as also shown in fig. 8, and, consequently, when the said clamp-has been closed upon the body oi'a wire-lmlder, and has then been placed within the lower end of the body of the metallic supporter a b, the said clamp will firmlyhoid the wireholder in its proper position during the process of depositing the combining and insnlating-material within the body of said metallic supporter, and around the shank of said wire-holder, and simultaneously therewith the annulargroove 1) formed in the head of the clamp h h gives the proper shape to the pendent portion 3 of the said combining and insnlatirig-material g, as represented in fig. 8, and modified forms of which are represented by figs. 2, 3, and 4.

A large number of the clamp-sections It may be cast in one piece, with a connecting-bar, k, as shown in figs. 9 and 10,-which will enable a large number oi the wire-holders and the metallic supporters of my improvedinsulator for telcgraph-wires to be preliminarily combined with each other, and then raised to the proper temperature for the reception within the body of said supporter of the permanently combining and The open portion of the. body a of the supporter, which descends below the combining and insulatingmaterial g, serves the purpose of protecting said material from any vertically or obliquely descending moisture; and the pendent portion s of said insulating-material that descends between the wire-holder and the open inner sides of the body of the supporter prevents the moisture that may condense upon the surface of said wire-holder from being brought into conducting-connection with the moisture that may condense upon the said open inner surface of the body of the supporter. And, as, an additional protection, the said metallic surfaces may be coated with varnish, or with any non-conducting tenacious cement, or may be glazed. Or, should it be deemedstill more expedient, some nonconducting and non-condensing cement may be run into the angle between the body of the wire-holder and the inner surface of the non-conducting pendent s, as shown by n n in fig. v1.

1 do not-intend to limit myself to any precise shape of the respective metallic portions of my improved insulator for telegraph-wires, while they sliall'be ofsnch a shape as will enable the said parts to be first preliminarilycombined with each other by a molding and clamping device preparatory to said parts being afterward permanently combined with each other by some insulatiug-material to be-placed, while in a plastic or fluid condition, within the body'ol' the metallic supporter, and around the shankof the wire-holder of said insulator, substantially as herein set forth.

" The shank b, which projects from the body a of the supporter a b, may be of any desired length, and may be of any shape that will best adapt my improved in sulator for telegraphic wires, to be made fast'eit-her to a vertical post,--or to a horizontal beain or arm.

The said shank may have screw-threads cast time upon, as shown in figs. 1 and 4, or the outer end of said shank may terminate in 'a perforated shield, t, as shown in Figure 11.

If it should be desired to give my improved insulator for telegiaph-wires the capacity of being secured to the upper side of a horizontal arm, the shank b must be curved or angnlarly tumed downward, and must be supplied with a. perforated flange or other equivalent device to prevent the turning of the insulater upon the axis of the said supporting-shank.

herein set forth.

2 Should it be desired to give my said improved insulator the capacity of being secured to the under side of a horizontal arm, the shank b of its supporter must be curved or angular-1y turned upward. and be supplied with some contrivanoe for securing the same to said arm.

The curve 0 in the wireholder, acting in conjunction with the concavities ffin the prongs d d of said holder, will prevent the telegraph-wire from being lifted out of the wire-holder while .the line is passing over considerable inequalities of surface.

In the matters of lightness, strength, durability, and I perfection of insulation under all circumstances, it is believed that this, my improved insulator for telegraph-wires, will excel all others; and it is also believed that its cost of production will be considerably less than that of any other perfect and durable insulator.

ZENAS 0. nosnms.

Witnesses:

' W. Moams SMITH,

SYDNEY E. SMITH. 

